Don Cheadle travels to Texas to talk to residents of Plainview about a drought that has led to the massive death of cattle, the closing of a major beef-processing plant and the loss of thousands of jobs. A fascinating debate between religion and science ensues. Harrison Ford flies to Indonesia to explore its dangerous deforestation. Ian Somerhalder of “Vampire Diaries” encourages young people to get involved in environmental issues. The main topic of this nine-part documentary series? Climate change and its scary effects on the planet. But the use of big stars — Jessica Alba, Matt Damon and more — as correspondents gives it the exciting feel of a big-budget action movie.